Separate RRDcached processes

Hi! I have a LibreNMS setup with two distributed pollers in a cluster serving different groups of devices. The main poller polls with frequency of 300 and the other with frequency of 15. Graphs on the second poller stopped showing after the frequency change (due to the wrong rrd step value, I suppose). I started a separate rrdcached process on the second poller and changed its config to use localhost instead of the core server’s process. On the second machine I set
$config[‘rrd’][‘step’] = 15;

lnms config:get --dump | jq shows the correct values of rrd step:
“rrd”: {
“heartbeat”: 30,
“step”: 15
},

But still, the graphs on devices polled by the second poller are not drawn. Do you have any idea how to fix this issue?